Calculate the dimensions of the glulam beams?

[RtZ]

I am sketching how to lay the roof on my planned extension. The dimensions for the room's outer walls will be 5.5m*4.2m. And the image "tillbyggnaden_a.jpg" shows how I want to place the glulam beams.

Inside the extension, I planned to cast a small supporting a wall and on top anchor a load-bearing beam. See image "takkontruktion_2.jpg". Is this a bad option? I just want to feel extra secure, simply put.

I am considering what dimension I need for the glulam beams, how I can calculate it myself, and how closely to place them? I live in snow zone 2. The roof slope will be 8 degrees.

Grateful for some tips and help.

 

[Enk Projektet]

Look here
http://www.moelven.com/se/Produkter-och-tjanster/Limtra/lagerbalksprogram/

 

[RtZ]

It was an interesting calculation program

I chose the following values:
Göteborg snow zone: 1.5
Self-weight roof construction: 0.45 kN/m² - Sheet metal roof with insulation and felt
Roof slope: 5 degrees
Center distance (c/c) of roof beams: 1200mm
Roof beam cantilever (u in the figure): 400mm
Horizontal length of roof beam (free span) L=: 4000mm

There was no option for 8 degrees, so I chose 5 for the sake of example. But a larger slope should presumably require somewhat less? And I got the result according to the attached image. But I don't know exactly how to interpret the result. Deflection I can guess means how the roof will sag downwards? But Dim Column Load??

Have I calculated the load correctly? I want a sheet metal roof and insulation. Underneath a bit of cladding like wood panels and gypsum, lights, etc. Is the dimension 66*315 a good choice? It gives at least quite little deflection.

 

[Mikael_L]

First and foremost ... I am not a designer.

66x315 seems great. You can probably manage fine with 56x225 as well, but the 315 beams provide a margin to switch to heavier roofing materials in the future, such as concrete tiles.
Then there's the issue of insulation; if you are thinking of 300mm insulation, you have the space for it already. OK, a bit more expensive, but I think it's relatively marginal compared to a 56x225 beam and then a lot of extra studs for insulation purposes.

I don't really know what the standard dimensions for glulam are, but if 56x315 exists, I would choose it myself.

But now to your next big problem. Where should the 6 tons of compressive force from the posts go?
Have you considered whether the foundation can withstand that pressure?

6 tons in point load usually require reinforcement of the concrete slab.
For example, a 200 mm thick slab and double reinforcement on about 1 sqm area around the load.

 

[prototypen]

Mikael I know you know that 6.0kN only corresponds to 600 kg.

Protte

 

[Mikael_L]

:blushing: :blushing:

Yes, I wrote that I'm not a designer ...

 

[Enk Projektet]

Not concrete tiles on an 8-degree slope....